The present invention relates to cable television ("CATV") systems. In particular, the invention relates to CATV systems in which individual subscribers have the ability to select specific programming, independently of other subscribers.
The present invention relates to a system which can be an integral solution to the problem of providing video program distribution where multiple subscribers are connected to a single coaxial feed via splitters. Heretofore, such systems often required that if an individual subscriber wished to view a specific program, i.e., a movie, then he had to wait until a specific start time for that movie. In many settings, it was desirable to be able to provide individual subscribers with the ability to select the specific program which they wanted to see, independently of any other subscriber, and to provide them with the capability of starting that program whenever they wished, i.e., so-called "Video-On-Demand". In such systems, each subscriber is able to request and receive Video-On-Demand without affecting other subscribers or viewing the programming selected by other subscribers.
The problem which has existed heretofore is that it has not been possible to readily provide Video-On-Demand to those CATV installations which had either been previously wired in a one-to-many arrangement, or which are currently being considered for wiring in a one-to-many arrangement, due to cost or space constraints. By way of example, in addition to residential CATV, commercial examples of CATV systems using a one-to-many arrangement would include cruise ships and college campuses. As the term is used herein, a "one-to-many" wiring arrangement refers to the splitting of multiple taps off a single coaxial cable, rather than wiring each endpoint in a star topology back to a central location, such as a wiring closet. The one-to-many arrangement is commonly in use, as such wiring has traditionally been considered to be a particularly attractive and cost effective approach to use with many CATV installations, because it was previously assumed that only a finite set of programs would be broadcast, even if some were scrambled for non-subscribers.
The downside of the one-to-many wiring arrangement is that we are now left with the legacy of those installations, even though the trend of what is expected of video distribution systems is rapidly moving toward "Video-On-Demand". Video-On-Demand must support "individually addressable subscribers", notwithstanding the current widespread use of the one-to-many wiring systems.